Detailed Description

Some generic 3D operations that are applicable to all features are defined here as static methods.

Attention

The convention for a feature descriptor is:

if the nearest neighbors for the query point at which the descriptor is to be computed cannot be determined, the descriptor values will be set to NaN (not a number)

it is impossible to estimate a feature descriptor for a point that doesn't have finite 3D coordinates. Therefore, any point that has NaN data on x, y, or z, will most likely have its descriptor set to NaN.